[shannonswyatt]

I need to build some outer covers and I have some 15/32 plywood. I was thinking of using the plywood that I have and then putting a 3/4 inch piece of foam insulation on top of it. I would think that would keep them cooler in the summer, warmer in the winter, but I wasn't sure if this is a bad idea or not. I know that some folks put insulation on the inside of the top cover and leave it year round, I just figured that since I am making them from scrape I might as well sandwich the insulation between the plywood and the top sheathing. Does anyone have any opinion on this, good or bad?

 

[jbraun]

Shannon,

Are you planning on using flashing as your top sheathing? I just made mine without insulation but I think that would work great. All you need to do is protect it with the metal and it should last a long time.

Good luck.

 

[db_land]

Shannon,
Years ago I constructed a bunch of tops with rigid foam insulation sandwiched between the sheets. Metal top, painted, etc. A bit heavy but worked fine. BUT, over time (maybe a year later), ants moved into the insulation area and loved it there. I couldn't get them out without de-constructing the tops.

 

[shannonswyatt]

Good point on the ants! I was thinking that if I used a bunch of contact cement between the plywood and the foam I could keep critters out. Sounds like you didn't have luck though. I wish I had some Advantec for the wood, since it won't hold water.

 

[psfred]

I cut a dado to fit the plywood and use 2.5" x 3/4" wood for the frame, setting the plywood 1/8" deeper than the top of the sides. I fill the space with newspapers to pad the flashing up so water runs off.

I suspect putting the insulating foam under the top cover in the winter would be easier than putting it under the flashing, although if you cut a dado down far enough you would be fine with it on top. You could always glue a sheet of 1/4" luan plywood on top of the foam, making sure that you seal it all the way around, that will keep the ants out.

Ants will chew the foam and make a nest if they get in, so you would need to make sure it was sealed all the way around top and bottom.

I like the idea of extra insulation in the summer to -- after all, hives are "naturally" found in trees, which are solid above the nest, not a thin sheet of wood.

Covered with aluminum flashing the plywood will last essentially forever on a hive. I do paint the parts exposed to the weather though, just because, both inside the frame and the parts of the plywood that are open to the air.

Peter

 

[shannonswyatt]

Good idea! I didn't even think about some luan and then seal it.

I've never heard of putting paper on the top, but it makes sense. Would any bugs want to get up there to eat the newspaper?

 

[Chemguy]

One approach would be to just build the outer covers, then place a piece of foam insulation on top of it, with something to weigh it down. That way, you can add/remove the insulation at will.

 

[shannonswyatt]

True, my problem would be I would more than likely lose the insulation!

 

[psfred]

No bugs in the summer, the heat would cook them. No bugs in the winter, it's too cold. Nothing available to make a nest with, no ants. At least that is my assumption! I have not had anything under the flashing that I know of, although I must admit I've not removed it to check.

Peter

 

[shannonswyatt]

I thought of doing them this way based on the way I do covers on my top bar hives. On those I just use Coroplast attached to poly with epoxy and gorilla glue at the corners, and it is placed in a 1x2 frame, making it nice and light to remove. But in those there is essentially no wood, so ants wouldn't find a reason to nest in them. I think I will give it a shot on two and test them out for durability and for pests. If they fail to perform I'm just out mostly time.

 

[Michael Bush]

Assuming the nice blue or pink foam it will usually stand up to the sun for a few years. It will eventually get soft and disintegrate. Carpenter ants have been the bigger problem with that kind of foam. The soft white foam doesn't last well and isn't very strong.

 

[Acebird]

Just calk up the edges of the tin with silicone and the ants can't get in.

 

[shannonswyatt]

I will caulk it up.